The most common place for a leak to develop is where the opening port dog is installed through the lens. A single O ring provides the seal. Over time, the rubber looses its elasticity. It becomes stiff and can crack. As it is under constant compression against the lens, the shape of the cross-section changes from a circle to an oval. Eventually it may even compress enough that the outside cap will hit and grind on the surface of the lens.
Our simple repair kit includes sixteen "O" rings to fit your Lewmar opening ports. That is typically enough to refit all of the Lewmar ports on Catalinas up to and including the Catalina 42. It also includes a resealable tube of a silicone grease suitable for your tool kit. The O rings seal better, last longer, and the dog will turn more freely with the application of a bit of the grease. The O rings should be cleaned, and greased every season. The resealable container of silicone grease will be handy for other projects aboard as well. Kit is sufficient to rebuild 8 ports.
Instructions: Access the single attachment screw inside the boat. The screw is hidden under the plastic cap in the center of the dog. Pop the cap off with the tip of a knife blade (a screwdriver is too blunt to work) and you will find the screw inside. The O ring is on the outside of the port.
Fits "Old Standard" Lewmar opening port dogs